Broaching tool



June 13, 1950 J. SCHINNERER BROACHING TOOL 2 Sheets-Sheet 1 Filed Feb. 21, 1946 INVENTOR. i v]- Schinnerer W 1- 7k 6; ATTURNE S Ludw J1me 1950 J. SCHINNERER 2,511,298

BROACHING TOOL Filed Feb. 21, 1946 2 Sheets-Sheet 2 IN V EN TOR. Ludwig J Schin nePer AT TOR Patented June 13, 1950 UNITED STATES BROACHING T001:

Application February 21, 1946', .Serial No...649,305;

8- Cl'aima, (Cl. 29-35-13,.

This invention relates. to breaching machines nd. more. particularly to. machines. for cuttin external longitudinal. spline grooves in sha s.

The invention. has for. an object. to provide, a breaching machinethat has a stack/of. ann lar. internally toothed-breaches which are rigidly. supported in spaced relationand in, axial. alinement so as. to provide cooling chambers of. substantial" capacit between. them and having means ior creating relatively rapid flow of liquid. Coolant through. each, of. the chambers in order to eiiectively cool bo h the. breaches and he Work and. to carry away the chips u y hebroaches.

A. further object isv to provide a breach holder in. which the breaches are rigidly supported in axial alinement with. an elon a ed. haft guide so positioned. with r spect he reach s as, o prevent bending of. he shaft as, it. is. forced. y endwise press re. through the brea hes.

An additional o je of. he inven ion is. to provide cooling chambers that have tangentially disposed liquid; inlet openings so that the entering liquid. under pressure ha a whirling motion in the chamber and large lateral discharge openings through which the liquid coolant carrying the chips cut from. the worl; can freely discharge.

With the above and other objects in view, the invention may b said to comprise the breaching machines as illustrated in the accompanying drawings, hereinafter described andparticularly set. forth in the appended claims, tflgether with such variations and. modification; thereof as will, be apparent to one skilled in the art to, which the invention pertains.

Reference should be had to the accompanying drawings forming a part of this specification, which:

Fig. 1 is a top plan view of a breach holder and broach assembly embodying the invention;

Fig. 2 is a View partly in side elevation and partly in vertical axial section showing the broach holder and assembly;

Fig. 3 is a side elevation of one of the spacing rings;

Fig. 4 is a section taken on the line indicated at 4-4 in Fig. 1;

Fig. 5 is a horizontal section taken on the line indicated at 5T5 in Fig. 4;.

Fig. 6 is a top plan view of one of the annular broaches, and

Fig. '7 is a side elevation of the broach shown in Fig. 6.

Referring to the accompanying drawings, the device of the present invention includes a breach holder I which may be formed of a single block Hil of metal'having a fl n edbase 2 nd a c n r l vertical. bore. 3. opening to. the bot om. hereof. A eeun erbore-iopening t the t pof. heh ld r forms a, breach receiving chamber, the block being. formed to provide. an. e cl s n wall 5.

around the-broachreceiving chamber. A series f annular reaches 6, of c ndr ea o f t within the eunterbore 4, ach.- of the e heshaying; anupwardlydished disc-like body portion 1 provid d. i ecentr p ni g 8 nd a lazily: spaced internal teeth 9 which project into. the opening 8,. The teeth 9 taper downwardly and have nt rior ae sthat conf rm. o. an up wardl-y taper ng one o h the ee ha I p per clearanc r cu t n groo s in a r p ece that s-mored e dwis th o gh. the brea e it bein under t hat; he e th: of su s breaches gradually increase in size toward thebottom. of; the chamber so that each broaeh en-. larges the groove cut by the preceding breaches.

h b eache i are p efe of d ti al s ructien, ach having p i al n lan e H) which project downwardly from the disc por-. tion I. The upper end. of the Gounterbore 4 is. internallythreaded to receive a guide plug II which screws, into the upper end of the counters h re. he guide-p ug ll h vin an o ga e guide bore. [,2 that is. axia lyalined with the pen s of. the breaches and the bore 3. in the bottom of. the broach holder, The bore [2, may be formed in. a hardened steel bushing l3. fitting in the plug I. l. and the length of the bore [2 is whatever may. be. necessary to prevent bendi g of th sha ins b oache y en ise pres ure ex r ed there on by means of a hydraulic plunger or other suit= able pressure applying means. In order to increase the size of the chambers between the breaches 6, spacing rings l4 may be provided which are cylindrical in form to fit in the counter-bore 4, the rings Ill being of the same thickness as the depending flanges l0 and forming extensions of the flanges Ill.

Each spacing ring [4 rests upon the top of a. breach 5 and provides a ledge upon which the spacing flange it) of the superimposed broach rests. Each spacing ring is provided with a P1111 l ty of l n a d no ches it ha ar a ap d. to register with circumferentially elongated open! ings l6 formed in the wall 5 and between the notches [5 the ring 14 are provided with holes ll that are adapted to register with horizontal passages l8 formed in the wall. 5. The passages It and openin erve to d l v a l u d 09 an nto ac of the chamb rs f rmed betwe n successive breache 6 and he passages l8 and openings II are arranged to deliver the liquid tangentially into the chambers so that the liquid has a whirling motion within the chamber. Means is provided for delivering liquid under pressure into the chambers through the passages I8 to cause a large volume of liquid to pass through each of the chambers and whirl about the shaft being broached and to contact with the broaches forming the top and bottom walls of the chamber 50 that heat is rapidly extracted from the broaches and the work. The elongated notches l5 and openings I6 permit the liquid carrying chips cut from the work to discharge freely from the cooling chambers.

The walls 5 of the holder I are provided with diametrically opposite thickened portions I9 in which vertical passages 20 are formed with communicate with each of the horizontal passages 18. Pipes 2| leading to a suitable coolant supply pump are connected to the passages 20. An external shield 23 is preferably provided around the wall 5 and spaced radially therefrom to provide an annular passage for discharge of coolant.

The broaches 5 and rings 1 are preferably assembled and secured together as a unit for insertion into the holder I and removal therefrom. As shown in Figs. 5 and 6, the broaches E are provided with diametrically disposed axial- 1y extending grooves 24 and the rings M are provided with similar grooves 25 adapted to register with the grooves 24. Positioning bars 25 and 2? are secured in the alined grooves 24 and 25 of the broaches 6 and rings I4 and are secured to the rings and broaches by means of screws 28. The bar 21 is preferably formed to fit in the grooves 24 and 25 with its external face flush with the cylindrical surfaces of the rings and broaches. The opposite bar 21 may be of a thickness slightly greater than the depth of the grooves 24 and 25 so as to project past the cylindrical surfaces of the broaches and rings to fit in an axially extending groove 29 formed upon the interior of the counterbore 4 so that both the notches l4 and openings l6 of the spacing rings are correctly registered with the openings IE and passages l3 of the wall 5. The stack of broaches is held in place in the chamber by any suitable means such as the guide plug II which may clamp the stack of broaches against the bottom of the counterbore 4.

It is to be understood that variations and modifications of the specific devices herein shown, and described for purposes of illustration, may be made without departing from the spirit of the invention.

What I claim is: 1, In a broaching machine, a broach stack having disc-like body portions provided with central internally toothed openings and peripheral spacing portions forming substantially internally cylindrical walls of greater diameter than said openings that enclose cooling chambers between said disc-like portions, said spacing portions having inlet and discharge openings to each of said chambers, said inlet openings being tangentially disposed and said outlet openings being circumferentially elongated, and means for delivering a liquid coolant under pressure through the tangential inlets into the cooling chambers to impart a whirling motion to the liquid in the chambers to wash out chips through the discharge openings.

2. In a broaching machine, a broach holder provided with a broach receiving chamber having an enclosing wall and an end wall provided with a central opening, said enclosing wall having axially spaced pairs of diametrically opposite inlet ports and circumferentially elongated discharge openings circumferentially alined with said ports, annular internal tooth broaches fitting within said enclosing wall and disposed in axially spaced relation, said broaches being positioned between successive pairs of inlet ports, and means for delivering a liquid coolant under pressure through said inlet ports into the spaces between said broaches.

3. In a broaching machine, a broach holder provided with a broach receiving chamber having a substantially cylindrical enclosing wall and an end wall provided with a central opening, said enclosing wall having axially spaced pairs of diametrically opposite tangentially disposed inlet ports and circumferentially elongated discharge openings circumferentially alined with said ports, annular internal tooth broaches fit.- ting within said enclosing wall, spacers between successive broaches providing cooling chambers, each open to a pair of said inlet ports and the discharge openings circumferentially aligned therewith and means for delivering a liquid coolant under pressure through said inlet ports into said cooling chambers.

4. In a broaching machine, a broach holder provided with a broach receiving chamber having a circumferential. wall provided with axially spaced inlet ports and circumferentially elongated discharge openings circumferentially alined with said ports, said chamber having an end wall with a central opening, a guide member forming the opposite end wall of said chamber, said guide member having an axially elongated guide opening alined with said central opening, a series of axially spaced broaches mounted in said chamber between the end wall and guide member, said broaches having openings alined with the end openings to said chamber and having internal cutting teeth, substantially internally cylindrical spacers of an internal diameter greater than said openings interposed between peripheral portions of said broaches, said spacers being provided with openings that register with said ports and elongated openings that register with said openings of the circumferential wall, and means for delivering a liquid coolant under pressure through said ports into said cooling chambers.

5. In a broaching machine, a broach holder provided with a broach receiving chamber having a circumferential wall provided in axially spaced portions thereof with a pair of diametrically opposite tangentially disposed inlet ports and circumferentially elongated discharge openings be tween the inlet ports of each pair, a series of annular internal tooth broaches in said chamber, said broaches being spaced axially and positioned between said pairs of ports to provide cooling chambers between them, and means for delivering a liquid coolant under pressure through said ports into said chambers to cause said liquid to whirl about the work and to wash chips through said elongated wall openings.

6. In a broaching machine, a stack of annular internal tooth broaches having cylindrical peripheries, each provided with diametrically opposite axially extending grooves, the grooves of all the broaches being alined, bars fitting in the alined grooves, one of said bars having its outer surface flush with the cylindrical peripheries of the broaches, the other of said bars extending past the cylindrical peripheries of the broaches and means for detachably securing said bars to certain of said breaches.

7. In a breaching machine, a stack composed of annular internal tooth breaches with annular spacers between them, said breaches and spacers having cylindrical peripheries of the same diameter, said breaches and spacers having diametrically opposite alined grooves, said spacers having circumferentially spaced openings, bars fitting in said grooves and extending substantially the full length of the stack, and means for detachably securing said bars to the end breaches of the stack to hold the breaches and spacers in assembled relation.

8. In a breaching machine a breach holder having a central bore opening to one end and a counterbore opening to the opposite end and forming a breach receiving chamber, said holder having axially spaced tangential inlet ports opening to said chamber and discharge openings circumferentially alined with said ports, a stack of annular breaches in said chamber, said breaches having cylindrical peripheries fitting in said counterbore, annular spacing means interposed REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 582,081 Newton May 4, 1897 2,078,632 Halborg Apr. 27, 1927 FOREIGN PATENTS Number Country Date 408,992 Great Britain Apr. 23, 1934 419,276 Great Britain Nov. 8, 1934 

